What are some of the hallmarks or conventions of the poetic form of the ode ?

What are some of the hallmarks or conventions of the poetic form of the ode ?

A. Simplicity in language, brevity in form, and humorousness in attitude
B. Complexity in language, lengthiness in form, and seriousness in attitude
C. Simplicity in language, lengthiness in form, and humorousness in attitude
D. Complexity in language, brevity in form, and humorousness in attitude